The subject matter disclosed herein relates to chemical and biological sensors, and more particularly, to chemical and biological sensors for gas dosimetry.
Chemical and biological sensors are often employed in a number of applications where the detection of various vapors may be used to discern useful information. For instance, measuring the presence of vapors by discerning a change in certain environmental variables within or surrounding a sensor may be particularly useful in monitoring changes in biopharmaceutical products, food or beverages, monitoring industrial areas for chemical or physical hazards, as well as in security applications, such as residential home monitoring, home land security in airports, in different environmental and clinical settings, and other public venues wherein detection of certain harmful and/or toxic vapors may be particularly useful. In addition, it may be desirable to measure the concentration of a vapor over time, which may be referred to as dosimetry.
One technique for sensing such environmental changes is by employing a sensor, such as an RFID sensor, coated with a particular sensing material. In addition, sensors may be arranged in an array of individual transducers, which are coated with one or more sensing materials. Many sensor arrays include a number of identical sensors. However, while using identical sensors simplifies fabrication of the sensor array, such an array may have limited capabilities for sensing only a single response (e.g. resistance, current, capacitance, work function, mass, optical thickness, light intensity, etc). In certain applications multiple responses or changes in multiple properties may occur. In such applications, it may be beneficial to include an array of sensors wherein different transducers in the array employ the same or different responses (e.g. resistance, current, capacitance, work function, mass, optical thickness, light intensity, etc.) and are coated with different sensing materials such that more than one property can be measured. Disadvantageously, fabricating a sensor array having individual sensors uniquely fabricated to sense a particular response, complicates fabrication of the array.
Further, in many practical applications, it is beneficial to use highly selective chemical and biological sensors. That is, it is often desirable to provide a sensor array capable of sensing multiple vapors and vapor mixtures in the presence of other vapors and mixtures. The greater the number of vapors and vapor mixtures that may be present, the more difficult it may be to accurately sense and discern a specific type of vapor or vapor mixture being sensed. This may be particularly true when one or more vapors are present at levels of magnitude greater than the other vapors of interest for detection. For instance, the presence of certain contaminants may interfere with the accurate measurement of a specific vapor.
Various embodiments disclosed herein may address one or more of the challenges set forth above.